Sending packages by airplane is nothing new, but the task could soon be taken over by drones.

DHL recently completed a three-month test of its automated drone delivery system, the Parcelcopter. It works with a combination helipad and mailbox dubbed Skyport, which can automatically load and unload the drone’s payload when it lands and store it in one of the station’s lockers.

Testing took place between January and March in Bavaria, Germany. The idea was to see if the drone could be used to deliver packages to remote areas where standard delivery takes a long time.

According to DHL, the Parcelcopter successfully completed 130 autonomous loading and unloading cycles while dealing with rapidly changing weather conditions and temperature fluctuations. Each round trip covered 8 kilometers with the drone flying 1,200 meters above sea level. Flying at a speed of 70 km/hour, the Parcelcopter was able to deliver its payload within 8 minutes of take-off. A trip that takes 30 minutes by car in winter.

This latest round of testing is part of a larger research and innovation project that DHL has been working on since 2013, when the company’s first generation Parcelcopter was used to deliver medication from one bank of the Rhine river in Bonn to the other. DHL has made a number of improvements to their newest drone model including increasing its payload allowance from 1.2kg to 2kg and upping its altitude limits for flight in mountainous terrain.

Of course, other companies are also hoping to get involved in drone delivery. Amazon and Google have been testing their own drones, while UPS has partnered with startup Zipline to deliver vaccines and blood to remote areas in Rwanda starting in July.

DHL has not said when its automated drone delivery service would be available to the public. In the U.S., not service can start until the Federal Aviation Administration makes a decision on how to deal with automated drones buzzing around in U.S. airspace.